Place pomegranate arils (reserve a few for garnish), 2 cups water and agave syrup in a blender.  Blend until smooth.  

Place remaining water in a large pitcher.  Add blended pomegranate mixture to pitcher through a mesh strainer.  Add lime juice.  Adjust sweetness if needed. 

Serve over ice.  Garnish with lime slices and pomegranate arils.